Artichoke Cultivars (var. “Blanca de Tudela”) under Elevated Ozone Concentrations (original) (raw)
Related papers
Two globe artichoke cultivars (Violet de Provence and Apollo) were harvested at an experimental field in Sicily, immediately washed with ozonised water and stored in: i) normal atmosphere; ii) ozone-enriched atmosphere for 3 days and for the last 4 days in normal atmosphere; iii) ozone-enriched atmosphere for 7 days. A control (samples unwashed and stored at room temperature) was also investigated. The effect of cultivar x ozone treatment interaction on water content losses, total polyphenols content and antioxidant activity was evaluated after 0, 3 and 7 days of storage. Washing with ozonised water and storage under O3enriched atmosphere allowed higher water retention compared with the control, especially for Violet de Provence. After 3 days of storage in ozone-enriched atmosphere, on average of cultivars, the total polyphenols content and antioxidant activity increased by 11.7% and 5.5%, respectively. By contrast, after further 4 days of storage in ozonised atmosphere, Apollo and Violet de Provence displayed a significant reduction in their level of total polyphenols and aantioxidant activity. The exposure of globe artichoke heads to an ozone-enriched atmosphere should not exceed 3 days aimed at preserving their high nutritional value, with special emphasis on total polyphenols content.
Adverse effects of ambient ozone on watermelon yield and physiology at a rural site in Eastern Spain
New Phytologist, 1999
The study reported was conducted to establish the impacts of photochemical oxidants (primarily ambient ozone, O $ ) on the yield of watermelon (Citrullus lanatus) at a site on the east coast of Spain. Fruit yield and quality were monitored in plots established in a commercial watermelon field exposed, in open-top chambers (OTCs), to nonfiltered air (NFA ; near-ambient levels of ozone) or charcoal-filtered air (decreased levels of photochemical oxidants including O $ ; CFA), or to ambient air (AA), during the 1988 and 1989 growing seasons. Ambient levels of O $ were found to exceed present UN-ECE (United Nations Economic Commission for Europe ; Convention on Long-Range Transboundary Air Pollution) critical level guidelines for the protection of crop yield by approx. twofold in 1988 and by approx. fivefold in 1989. Plants exposed to NFA and AA developed visible O $ injury on the upper surface of sun-exposed older leaves, and fruit yield (annual marketable fruit weight and number) was found to be depressed in OTCs ventilated with NFA in comparison with those receiving CFA. Consistent with inter-annual variations in O $ exposure, greater yield losses were experienced in 1989 (39%) than in 1988 (19%), an effect mediated predominantly by a decline in fruit number rather than average fruit weight. Exposure to ambient levels of ozone also slightly decreased fruit quality (4-8% decline in soluble solids content). Leaf gas exchange measurements made in the field in 1988 revealed effects of O $ on fruit yield and quality to be associated with a decline in the net CO # assimilation rate per unit leaf area under light saturation (A sat ) and stomatal conductance to water vapour (g s ), and enhanced rates of dark respiration. A\c i curves (where A is the net CO # assimilation rate per unit leaf area and c i is the mole fraction of CO # in the leaf intercellular air space) constructed for plants grown in laboratory-based closed chambers, and exposed to an accumulated O $ exposure similar to that experienced by plants in the field, suggested that the likely cause of the decline in photosynthetic capacity was (1) a decrease in the amount and\or activity of Rubisco and (2) an impaired capacity for regeneration of ribulose 1,5bisphosphate, which was not mediated through changes in the photochemical efficiency of photosystem II (F v \F m , where F v is variable chlorophyll a fluorescence and F m is maximum chlorophyll a fluorescence). No shift in the relative stomatal limitation to photosynthesis was observed under the influence of O $ , suggesting that the decline in g s induced by the pollutant in both field and laboratory was the result, and not the cause, of the decrease in A sat . Ozone exposure also caused a decrease in C isotope discrimination (approx. 0.5=), a shift that revealed a departure from predicted theory based on supporting leaf gas exchange measurements. The study demonstrates that ambient levels of photochemical oxidants on the Spanish Mediterranean coast are high enough to adversely influence the yield and physiology of an economically important crop grown in the region, and the magnitude of the effects was
1998
A field study was conducted from May to October 1995 to assess ozone (O3) phytotoxicity in Catalonia (NE Spain) by determining a percentage value of leaf area injured by ozone on three tobacco cultivars, Bel-W3, Bel-C and Bel-B as bioindicators. Colorimetric parameters were also determined in an effort to have an objective assessment of ozone injury. The study was conducted simultaneously on eight sites where ozone levels and several meteorological parameters were continuosly monitored. Two sets of plants were used at each site. The first one was composed of six plants of each cultivar which were changed every two weeks while the second one involved two plants of each cultivar which were kept in the plots throughout the whole experimental period. Open Top Chambers were also used to test the response of the three cultivars to ozone under controlled conditions. The ozone levels correlated well with ozone injury on the Bel-W3 cultivar but not as well on the other two cultivars. The ozone levels did not fully account for all the observed injury. The response of tobacco plants to ozone concentrations and therefore its biomonitoring capacity depended also on different environmental conditions linked to stomatal behaviour such as temperature, humidity, wind or altitude. These environmental conditions had some effects on the intensity of Ozone injury. Ozone concentrations accumulated over a threshold of 60 ppb (AOT60) when VPD was below 1 KPa. Correlated well with the ozone injury and best explained the intensity tobacco injury symptoms. For large plants growing throughout the whole period of study, Bel-C was the best indicator cultivar for AOT60 over the 3 days prior to the last ozone injury assessment. The colorimetric parameters were indicators of seasonal changes but they were not good ozone damage indicators. It is concluded that tobacco cultivars were good bioindicators but meteorological and other environmental factors need to be considered in there use as biomonitors.
Environmental Pollution, 1993
Two cultivars of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo), which are widely grown in Spain, were exposed to ozone (70 nl litre -l, 6 h d 1) for 21 days. Ozone sensitivity was assessed by recording the extent of visible injury, changes in fast-fluorescence kinetics, the relative-growth rate (R) of root (RR) and shoot (~s), and effects on the number of flowers produced per plant. Leaf gas exchange was measured in order to provide some indication of the factors underlying differential response to ozone. After 9-10 days of fumigation, all the cultivars developed typical visible symptoms of ozone injury on the older leaves. However, significant (P < 0.05) changes in fast-fluorescence kinetics were detected prior to the development of visible foliar injury, indicating that detectable effects of ozone on primary photochemical processes supersede the appearance of visible symptoms. In both muskmelon and watermelon, there was a marked reduction in the rate of C02 assimilation as a result of exposure to ozone, and this was accompanied by a parallel decrease in stomatal conductance. Mean plant-relative-growth rate (R) was markedly (P < 0.01) suppressed by ozone in the two cultivars of watermelon, but there were no significant effects on R in muskmelon. Ozone reduced root growth relative to the shoot in three out off our cultivars---an effect that may be of considerable ecological significance. Moreover, exposure to ozone reduced flower production in both muskmelon and watermelon, which indicated effects on yield There was no correlation between a variety of methods used to assess ozone sensitivity and visible injury, and reasons for this are discussed. This observation draws clear attention to the dangers in ranking plants for ozone sensitivity purely on the basis of visible symptoms. It is concluded from this study that ozone-insensitive genotypes should be identified and considered for planting in the major areas of melon production concentrated on the Mediterranean coast of Spain.
An international cooperative programme indicates the widespread occurrence of ozone injury on crops
Agriculture, Ecosystems & Environment, 2000
The UN/ECE ICP-Vegetation 1 routinely investigates the effects of ambient ozone pollution on crops throughout Europe. Each year, a series of co-ordinated ambient air experiments are conducted over a large area of Europe and a range of crop species are observed for the occurrence of injury following ozone episodes. In 1995 and 1996, ozone injury was observed at sites throughout Europe from United Kingdom (Nottingham) to the Russian Federation (Moscow) and from Sweden (Östad) to Italy (Naples). The only site participating in the ICP-Vegetation where it was not observed was that at Finland (Jokioinen). Injury was identified on subterranean and white clover, French bean, soybean, tomato, and watermelon at one or more sites. Injury was also detected in gardens and on crops growing in commercial fields. Two short-term critical levels which incorporate ozone dose and air saturation vapour pressure deficit (VPD) were derived from the 1995 data. These were (i) an AOT40 2 of 200 ppb.h over 5 days when mean VPD (0930-1630 h) is below 1.5 kPa and (ii) an AOT40 of 500 ppb.h over 5 days when mean VPD (0930-1630 h) is above 1.5 kPa. In general, the 1996 data supported these critical levels although injury did occur on two occasions when the AOT40 was less than 50 ppb.h, and the VPD was less than 0.6 kPa. Thus, ICP-Vegetation experiments have shown that ozone injury can occur over much of Europe and that plants are most at risk in conditions of high atmospheric humidity.
Atmospheric Environment, 2006
Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic-exposed sites. The tobacco plants were exposed to ambient air for biweekly periods at up to 100 biomonitoring sites from 2000 to 2002. Special emphasis was placed upon methodological standardisation of plant cultivation, field exposure and injury assessment. Ozone-induced leaf injury showed a clearly increasing gradient from northern and northwestern Europe to central and southern European locations. The strongest ozone impact occurred at the exposure sites in Lyon and Barcelona, while in Edinburgh, Sheffield, Copenhagen and Du¨sseldorf only weak to moderate ozone effects were registered. Between-site differences within local networks were relatively small, but seasonal and inter-annual differences were strong due to the variability of meteorological conditions and related ozone concentrations.
Biomonitoring ozone phytotoxicity in eastern Spain
Water, Air, & Soil Pollution, 1995
High ozone (03) levels have been recorded in eastern Spain. A project was developed to identify the areas of elevated O3 and determine if these levels were above critical concentrations for plant damage. Thus. a network of bioindicators was established in two Autonomous Communities of Spain: Catalunya (31.930 km 2) and Valencia (23.305 km 2) to assess 03 phytotoxicity. Three tobacco cultivars, (Bel-W3, Bel-C and BeI-B) were used during the 1994 growing season in both Regions. In Catalunya the highest 03 phytotoxicity was recorded in coastal areas, while the phytotoxicity decreased as plants were grown further in-land. A lower 03 phytotoxicity was observed in coastal sites of the Valencia Autonomous Community, compared to Catalunya, although the O~ injury was observed downwind from Valencia city in the most resistant cultivar BeI-B. The results in the Valencian Community were difficult to interpret, since plant viruses were widely distributed, not only in indicator plants, but also in commercial crops grown in the area. The analysis of O3 concentrations, meteorological parameters and visible injury at the Catalan sites showed that high relative humidity levels could favour 03 phytotoxicity. Therefore, the interactions between O3 exposure and environmental conditions on plant response should be further studied for the establishment of sound critical levels.
Journal of applied biology and biotechnology, 2020
Tropospheric ozone is a phytotoxic gaseous pollutant with global warming potential that disrupts the plants growth and development directly or through climate change. Ozone enters into a plant's body through stomatal pores and develops oxidative stress, which results in injury to foliage and modifies leaf micro-morphology and anatomy. A field study was conducted to assess the morphological, micro-morphological, and anatomical response of groundnut cultivars (Arachis hypogaea L.) to enhance the level of ozone. This study observed ozone-like visible injury symptoms on all groundnut cultivars. Visible injury was maximum in cultivar Dh-86 and minimum in cultivar TPG-41. Micro-morphological characteristics, such as increase in stomata, epidermal cells number, and its index, were also increased under enhanced ozone-exposed plants. The highest stomatal index was found in cultivar TPG-41 and lowest were noted in cultivar GG-20. Cultivars TAG-24 > TG-37A > and Dh-86 show moderate modification in the morphological and micro-morphological characteristics of plants. Elevated ozone also affected the stomatal movement and leaf internal tissue. Most of the stomata of all the groundnut cultivars were observed as closed during the enhanced ozone exposure, suggesting a protective mechanism from ozone stress. The study concluded that the micro-morphological and anatomical characteristics are important aspects to determine the effect of ozone on plants and to influence plants sensitivity to ozone. On the basis of these characteristics, cultivar TPG-41 was found to be less sensitivity, while cultivar Dh-86 was found to be highly sensitive to ozone pollution.
Italian Journal of Agronomy, 2008
An Open-Top Chamber experiment on two tomato cultivars (cv. Oxheart and cv. San Marzano) was carried out in Curno (Northern Italy) between June and September 2007. Two ozone treatments were applied for a 3.5 months period: Non-Filtered OTC (NF-OTC, 95% of ambient ozone) and Charcoal-Filtered OTC (CF-OTC, 50% of ambient ozone). Diurnal cycles of porometry measurements were performed during the season and allowed to draw a stomatal conductance model for each cultivar in order to calculate the ozone stomatal fluxes taken up by plants. Assessments on fruits yield were performed during the season, taking into account the number of fruits, their fresh weight and their marketability. In addition, measurements on the chlorophyll fluorescence of photosystems were carried out to assess possible negative effects on photosynthetic efficiency. Despite the two cultivars absorbed a similar ozone stomatal dose during the season (with an 8% difference), their responses to ozone treatments were totally divergent in relation to both fruits yield and photosynthetic efficiency. Plants of cv. Oxheart grown in NF-OTCs showed significant yield loss in the total weight of fruits (-35.9%) which is exclusively related to a decrease in the number of fruits produced (-35.7% of total fruits; -30.6% of marketable fruits), since mean fresh weight of fruits remained unaffected. Moreover the same plants displayed low values (in comparison to CF-OTCs plants) of the photosynthetic efficiency index (PI abs ) during the most intense period of ozone stress (July) occurred in the flowering stage of plants and at the beginning of fructification. Plants of the cv. San Marzano had an opposite response behaviour with an increase of the mean fresh weight of fruits in plants grown in NF-OTC (even if not statistically significant) and no difference in the number of fruits produced and in the values of photosynthetic efficiency.